Counter propeller for air propeller-driven craft



' Get 25, 192?,

I 1,4,7 R. WAGNER COUNTER PROPELLER FOR AIR PROPELLER DRIVEN CRAFT Filed Oct. 10, 1925 18. Wagner, y W %M/ZZ- moment acting on For transmitting the rotary moment Patented Get. 25, 1927.

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RUDOLF WAGNER, OF HAMBURG, GERMANY.

COUNTER PBOPELLER FOR AIR PROPELLEB-DBIVEN CRAFT.

Application filed October 10, 1925, Serial No. 61,724, and in Germany March 14, 1925.

This invention relates to counter propellers and more particularly to counter propellers mounted on airropeller driven crafts.

The counter prope ler is in general a fixed propeller mounted behind the main or ro-.

tating prgpellen considered in the direction.

of motion. The main propeller causes the fluid in which it operates to leave it in a rotary or Swirling movement, and the function of the counter propeller is to receive the rotary fluid currents and change their direction into an axial flow, and thus increase'the efiectiveness of the drive of the craft by imparting a forward thrust obtained from changing the rotary fluid currents into axially directed currents. In mounting a fixed counter propeller behind a mainpropeller in crafts driven b air propellers, and particularly; in aircra t having motor drive, there are certain difliculties as compared with "those of water'- craft. In the aircraft there is generally no structural part, such for example, as the rudder posts in watercraft, to which can be attached the counter propeller; Furthermore, in the air propelled craft the main propeller is relativel much larger than is the case in watercra y In any arrangement of the counter propeller independently of the shaft of the main propeller it is generally necessary to have relatively long arms connecting the counter propeller to the body of the craft, which arms ofier. additional air resistance.

This invention overcomes this difliculty mentioned above by mounting the counter propeller directly on a prolongation of the main propeller shaft so that the useful thrust of the counter propeller is transmitted to the main propeller shaft.v The rotary the counter propeller is taken up by a connection from the counter propeller to the body of the craft and this connection is arranged so as to form no. obstacle to the adjustment of the main propeller shaft. It is entirely feasible to mount the counter propeller directly on the main propeller shaft since this weight is slight and since it exerts no centrifugal or like forces.

of the craft body, in the counter propeller to the present construction only relatively thin tenson or thrust elements are necessary, and such elements ofier no appreciable air resistance.

.counter propeller which engages so as to function For taking up the rotary moment of the counter propeller there can also be used a prolongation of one ofthe blades of the 1n a grooved holding lug mounted on the craft body In the accompanying drawings merely by way-of example, are shown three forms of construction in accordance with this invention.

In the drawings:

Fig. 1 is a rear end elevation of the counter propeller arrangement connected to a motor driven lighter than aircraft.

Fig. 2 is a side elevation of the construction shown in Fig. 1.

Fig. 3 is a view similar to that of Fig. 1, of a slightly modified formof construction. Fig. 4 is a top plan view of a further form of construction as applied to a motor for heavier than air craft.

Fig. 5 is a rear'end elevation of the construction shown in Fig. 4.

Referring to Figures 1 and 2 an airship body is shown at1 with a gondola 2 to which is fitted a main air propeller 3 which rotates in the direction of the arrow of Fig. 1, for forward travel. A-four=bladed counter propeller 4 is journalled by means of ball bearings 5 on a prolongationof the main propeller shaft 5' so as to afford an axle guide for the counter propeller.

The turning moment'acting on the counter propeller due to the action therewith of the rotary off-flow transmitted through a loosely pivoted tension member 6, to the craft body 1, the member 6 being loosely mounted to permit free adjustment of'the propeller shaft 5.

-In the constructionas described the turning moment of the counter propeller tends to raise the counter propeller about the point 7 the connection between the member 6 and the counter propeller, so that there arises an upward force on bearing 9, in the direction of arrow 8 of Fig. 1. This upward force partly counterbalances the weight of the main and counter propeller so that the use of the counter pro-- eller as described above, results in more avorable conditions for the main propeller bearin than would otherwise exist.

Whi signed to take both tension and compression properly, on reverse rotafrom. the main propeller is the main propeller shaft x109 e the member 6 is preferably detion of the main propeller 3, if desired, a construction as shown in Figure 3 can be used wherein the member 6 is designed for tension only and a second member 10' designed for tension only is connected between the counter propeller and the craft body for ,takingu'p the turning moment of the counter propeller on reversal. of the direction of rotation of the main propeller.

' Referring to Figures 4 and 5 wherein the counter propellenarrangement is shown in connection with a motor driven heavier than aircraft, the craft is shown at 11 having wings 12 and a drive motor 13. The main propeller 14 is mounted on a shaft having an extended portion in the same manner as in connection with Figures 1 and 2. In

I this form of construction the counter propeller 15 which is mounted on the main proeller shaft has an extension 16 on one of its blades and this extension loosely engages in a'U-shaped holding lug 17 which is fixed to the body 11 of the craft.- This connection between the parts 16 and 17. prevents rotation of the counter propeller due to turning moment received from the rotat ng currents of fluid leaving the main propeller blades. Inthis construction the counter ropeller is held from rotation in both directions and, hence, is adapted for use with the main propeller rotating either forward or backward.

The U-shaped holding member 17 readily permits all necessary adjustment of the main of the weight of the propellers.

. propeller shaft, comprising a counter peller journaled on the main propeller s aft In addition to the above examples of construction in accordance with this invention the inventive idea. can of course be carried out in many other manners and furthermore, can of course be used for other than air ropeller driven craft. The invention can be readily used for land and Watercraft without exceeding the scope ofthe inventive idea. v v

Having now described my. invention, I claim:

1. A counter propeller device for craft which are driven by a main propeller on a '1n the path of the rotary air outflow from of the main propeller the main propeller, and a connection between the counter propeller and the craft body for taking u the turning moment of the counter prope er, the connection being constructed to permit acijupttment movements body for taking up a propeller shaft, comprising a counter propeller journaled on the main propeller shaft in the path of the rotary air outflow from the mainpropeller, and a connection between the counter propeller and the craft body for taking up the turning moment of the counter propeller, the connection acting at the end of a counter propeller blade and being constructed' to permit adjustment movements of the main propeller shaft; 3. A counter propeller for craft driven b propeller means, comprising, a cra havinga body, a main lpropeller, a shaft carrying the main propel er, a counter propeller journalled on anextended portion ofthe main propeller shaft and a connection between the counter propeller and the craft body for taking up the turningmoment of the counter propeller, the connection comprising, an extension on one of the counter propeller blades and a holding lug on the craft body loosely engaging the extension whereby to permit ready adjustment of the main propeller shaft. 1 4. A counter propeller device for craft which are driven by a main air propelleron a propeller shaft, comprising a counter propeller journaled on the main propeller shaft in the path of the rotary air outflow from the main propeller, and a connection between the end of a counter propeller blade and the craft body for taking up the turning moment of the counter propeller, said connection being constructed to permit adjustment movements of the main propeller shaft, and

connected to the counter propeller onthe descending side of the arcof rotation thereof wherebyv an upwardly directed force is caused by the reaction therewith of the turnmg moment of the counter, propeller. 5. A counter propeller for craft driven by a1r propeller means, comprising, a cra having a body, a main ropeller, a shaft carrylng the main propel er, a counter propeller journalled on an extended portion of the main propeller shaft and aconnection between the counter pfopeller and the craft t eturning moment of the counter propeller, the connection being arranged to permit adjustment of the main propeller shaft, and comprising, an exten sion on one of the counter and a holding lugi on the craft body engaging the extension, the connection 'bei so arranged that, on forward movement 2% the main prtgeller, an upwardly directed force is cause by the reaction therewith of the taming moment of the counter pro peller.

In testimony whereof. I have sied my name to this specification.

nunonr propeller blades, 

